/**
 * ***************************************************************************** Copyright (c) 2007,
 * 2012 IBM Corporation and others. All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0 which accompanies this
 * distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
 *
 * <p>Contributors: IBM Corporation - initial API and implementation
 * *****************************************************************************
 */
package org.eclipse.ltk.core.refactoring.resource;

import java.net.URI;
import org.eclipse.core.filebuffers.FileBuffers;
import org.eclipse.core.filebuffers.ITextFileBuffer;
import org.eclipse.core.filebuffers.LocationKind;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IResourceVisitor;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubProgressMonitor;
import org.eclipse.ltk.core.refactoring.Change;
import org.eclipse.ltk.core.refactoring.ChangeDescriptor;
import org.eclipse.ltk.internal.core.refactoring.BasicElementLabels;
import org.eclipse.ltk.internal.core.refactoring.Messages;
import org.eclipse.ltk.internal.core.refactoring.RefactoringCoreMessages;
import org.eclipse.ltk.internal.core.refactoring.RefactoringCorePlugin;
import org.eclipse.ltk.internal.core.refactoring.resource.UndoDeleteResourceChange;
import org.eclipse.ltk.internal.core.refactoring.resource.undostates.ResourceUndoState;

/**
 * {@link Change} that deletes a resource.
 *
 * @since 3.4
 */
public class DeleteResourceChange extends ResourceChange {

  private final IPath fResourcePath;
  private final boolean fForceOutOfSync;
  private final boolean fDeleteContent;
  private ChangeDescriptor fDescriptor;

  /**
   * Delete a resource.
   *
   * @param resourcePath the resource path
   * @param forceOutOfSync if <code>true</code>, deletes the resource with {@link IResource#FORCE}
   */
  public DeleteResourceChange(IPath resourcePath, boolean forceOutOfSync) {
    this(resourcePath, forceOutOfSync, false);
  }

  /**
   * Delete a resource.
   *
   * @param resourcePath the project path
   * @param forceOutOfSync if <code>true</code>, deletes the resource with {@link IResource#FORCE}
   * @param deleteContent if <code>true</code> delete the project contents. The content delete is
   *     not undoable. This setting only applies to projects and is not used when deleting files or
   *     folders.
   */
  public DeleteResourceChange(IPath resourcePath, boolean forceOutOfSync, boolean deleteContent) {
    Assert.isNotNull(resourcePath);
    fResourcePath = resourcePath;
    fForceOutOfSync = forceOutOfSync;
    fDeleteContent = deleteContent;
    setValidationMethod(SAVE_IF_DIRTY);
  }

  /* (non-Javadoc)
   * @see org.eclipse.ltk.core.refactoring.resource.ResourceChange#getModifiedResource()
   */
  protected IResource getModifiedResource() {
    return getResource();
  }

  private IResource getResource() {
    IResource resource = ResourcesPlugin.getWorkspace().getRoot().findMember(fResourcePath);
    if (resource == null && fResourcePath.segmentCount() == 1) {
      resource = ResourcesPlugin.getWorkspace().getRoot().getProject(fResourcePath.segment(0));
    }
    return resource;
  }

  /* (non-Javadoc)
   * @see org.eclipse.ltk.core.refactoring.Change#getName()
   */
  public String getName() {
    IPath path = fResourcePath.makeRelative();
    String label =
        Messages.format(
            RefactoringCoreMessages.DeleteResourceChange_name,
            BasicElementLabels.getPathLabel(path, false));

    if (path.segmentCount() == 1) {
      IResource resource = getResource();
      if (resource != null) {
        IPath location = resource.getLocation();
        if (location != null) {
          label =
              label
                  + BasicElementLabels.CONCAT_STRING
                  + BasicElementLabels.getPathLabel(location, true);
        } else {
          URI uri = resource.getLocationURI();
          if (uri != null) {
            label =
                label
                    + BasicElementLabels.CONCAT_STRING
                    + BasicElementLabels.getURLPart(uri.toString());
          }
        }
      }
    }
    return label;
  }

  /* (non-Javadoc)
   * @see org.eclipse.ltk.core.refactoring.Change#perform(org.eclipse.core.runtime.IProgressMonitor)
   */
  public Change perform(IProgressMonitor pm) throws CoreException {
    if (pm == null) pm = new NullProgressMonitor();

    pm.beginTask("", 10); // $NON-NLS-1$
    pm.setTaskName(RefactoringCoreMessages.DeleteResourceChange_deleting);

    try {
      IResource resource = getResource();
      if (resource == null || !resource.exists()) {
        if (fDeleteContent) return null; // see https://bugs.eclipse.org/343584
        String message =
            Messages.format(
                RefactoringCoreMessages.DeleteResourceChange_error_resource_not_exists,
                BasicElementLabels.getPathLabel(fResourcePath.makeRelative(), false));
        throw new CoreException(
            new Status(IStatus.ERROR, RefactoringCorePlugin.getPluginId(), message));
      }

      // make sure all files inside the resource are saved so restoring works
      if (resource.isAccessible()) {
        resource.accept(
            new IResourceVisitor() {
              public boolean visit(IResource curr) throws CoreException {
                try {
                  if (curr instanceof IFile) {
                    // progress is covered outside.
                    saveFileIfNeeded((IFile) curr, new NullProgressMonitor());
                  }
                } catch (CoreException e) {
                  // ignore
                }
                return true;
              }
            },
            IResource.DEPTH_INFINITE,
            false);
      }

      ResourceUndoState desc = ResourceUndoState.fromResource(resource);
      if (resource instanceof IProject) {
        ((IProject) resource)
            .delete(fDeleteContent, fForceOutOfSync, new SubProgressMonitor(pm, 10));
      } else {
        int updateFlags;
        if (fForceOutOfSync) {
          updateFlags = IResource.KEEP_HISTORY | IResource.FORCE;
        } else {
          updateFlags = IResource.KEEP_HISTORY;
        }
        resource.delete(updateFlags, new SubProgressMonitor(pm, 5));
        desc.recordStateFromHistory(resource, new SubProgressMonitor(pm, 5));
      }
      return new UndoDeleteResourceChange(desc);
    } finally {
      pm.done();
    }
  }

  private static void saveFileIfNeeded(IFile file, IProgressMonitor pm) throws CoreException {
    ITextFileBuffer buffer =
        FileBuffers.getTextFileBufferManager()
            .getTextFileBuffer(file.getFullPath(), LocationKind.IFILE);
    if (buffer != null
        && buffer.isDirty()
        && buffer.isStateValidated()
        && buffer.isSynchronized()) {
      pm.beginTask("", 2); // $NON-NLS-1$
      buffer.commit(new SubProgressMonitor(pm, 1), false);
      file.refreshLocal(IResource.DEPTH_ONE, new SubProgressMonitor(pm, 1));
      pm.done();
    } else {
      pm.beginTask("", 1); // $NON-NLS-1$
      pm.worked(1);
      pm.done();
    }
  }

  /* (non-Javadoc)
   * @see org.eclipse.ltk.core.refactoring.Change#getDescriptor()
   */
  public ChangeDescriptor getDescriptor() {
    return fDescriptor;
  }

  /**
   * Sets the change descriptor to be returned by {@link Change#getDescriptor()}.
   *
   * @param descriptor the change descriptor
   */
  public void setDescriptor(ChangeDescriptor descriptor) {
    fDescriptor = descriptor;
  }
}
